Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment, as examples. Semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductive layers of material over a semiconductor substrate, and patterning the various layers using lithography to form circuit components and elements thereon.
Semiconductor devices are typically packaged as single die or in multi-chip modules. Many different types of packaging are used, and packaging techniques have changed throughout the years as semiconductor devices are scaled down in size and according to the end application. Factors such as performance, size, weight, and operating conductions influence the type of packaging selected. In-line packages, small outline packages, quad surface mount, and array packages are examples of some major package families.
A recent trend in semiconductor packaging is three dimensional (3D) packaging or wafer stacking. Flip-chip packages are one such packaging technique, where gold bumps or solder ball techniques are used to bond one substrate to another. The use of through-silicon vias (TSV's) has been explored for 3D packaging interconnects, where two die or integrated circuits are bonded together and through-silicon vias, front side contacts, and back side contacts are used to make connections between the two die. However, alignment marks and alignment procedures are required to align the two die using this method, which requires additional manufacturing and processing steps and may result in misalignment between the die.
Thus, what are needed in the art are improved structures and methods for connecting together two die or workpieces.